Hello
bugster0121 
What firewall do you use?
The Web Shield process ashWebSv.exe or aswWebSv.exe needs to have access to internet and permission to act as server. Read this
http://support.avast.com/index.php?_m=know...;kbarticleid=22 and see if that can help you resolve the problem.
Other possibility is that you haven't uninstalled Norton antivirus properly, which could make avast! not to work correctly.